Providing the location of a manhole for access to utilities located underground usually requires the location of the precise point representing the center of an excavation to be transformed into the manhole. The size of the manhole (cylindrical with a predetermined diameter) is predetermined and the center of the proposed manhole is located. A circular marking is then provided as a guide for subsequent excavation and for planning layouts and locations of such excavations. The marking is usually executed by a workman anchoring a flexible tape (such as a flexible rule) or a chord to the center point of the proposed excavation and then progressively marking (with spray paint for example) points circumscribing the center point thus resulting in a circular marking on the ground or other working surface.